1. Field of the Invention
The present invention relates to a light emission device package and a method of fabricating the same.
2. Discussion of the Related Art
Cathode ray tubes (CRTs) are widely used as a display device. CRTs are used as computer monitors, televisions, displays for measuring apparatuses, information terminals, and so on. However, the heavy weight and large size of CRTs have made the manufacturing of smaller and lighter electronic products more desirable.
To address this matter, LCD devices are gradually being used in a wide range of applications due to their improved luminance, thinness, and power consumption. Furthermore, LCD devices are being manufactured to have even larger screens, be thinner, and consume less power, in order to meet requirements of users. Such LCD devices display images by controlling the amount of light transmitted through liquid crystal.
Unlike CRTs, LCD devices are not self-illuminating display devices. As such, an LCD device includes a backlight unit provided on the rear surface of an LCD panel. The backlight unit includes a separated light source providing the light necessary to display an image. The backlight unit is classified as either an edge type or a direct type backlight in accordance with the disposition of its light source.
The edge type backlight unit includes a light source disposed in a position corresponding to a side of the LCD panel. Also, the edge type backlight unit irradiates light emitted from the light source onto the entire surface of the LCD panel using a light guide panel. On the other hand, the direct type backlight unit includes a plurality of light sources arranged opposite the rear surface of the LCD panel. These plural light sources directly apply light to the rear surface of the LCD panel. The direct type backlight unit has a higher brightness and a wider luminescent surface than the edge type backlight unit because it employs plural light sources.
Recently, as the display size of the LCD device has increased, the size of the backlight unit has also increased. Accordingly, the direct type backlight unit is mainly applied to the enlarged LCD device.
The backlight unit may employ a plasma type light source, such as a cold cathode fluorescent lamp (CCFL), a hot cathode fluorescent lamp (HCFL), an external electrode fluorescent lamp (EEFL), an external and internal electrode fluorescent lamp (EIFL), or others as a light source. Alternatively, the backlight unit may use a light emission device (LED) as a light source. Among these light sources, the LED is widely used in the backlight unit because of its long lifespan, low power consumption, small size, high durability, and other desirable qualities.
LEDs are manufactured in a variety of packages. Among the LED packages, a ceramic LED package has a desirable thermal characteristic. As such, the ceramic LED package has been researched for use as a light source package of the backlight unit. However, a ceramic LED package of the related art is expensive to produce. Also, the ceramic LED package of the related art cannot minimize chromatic variation between light propagation directions (light radiation angles). Furthermore, the ceramic LED package of the related art is limited to a light radiating characteristic (i.e., a narrow light radiation angle or a narrow distribution of radiated light). For these reasons, it is difficult to apply the ceramic LED package to the backlight unit.
In other words, the related art LED package is positioned apart from the optical sheets due to its narrow distribution of radiated light (or its narrow light radiation angle) when it is used as a light source of the backlight unit. As such, the total thickness of the backlight unit is increased. Also, the related art LED package forces the difference (or the variation) between chromatic coordinates in accordance with its light propagation directions to be considerably enlarged. As a result, the related art LED package cannot provide chromatic uniformity to the surface of the backlight unit. Moreover, the related art LED package increases manufacturing costs because it is difficult to manufacture. For example, the manufacturing process includes the treatment of raw materials. Therefore, it is difficult for the related art LED package to apply to the backlight unit.